enc_writ.c

/* crypto/des/enc_writ.c *//* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com) * All rights reserved. * * This package is an SSL implementation written * by Eric Young (eay@cryptsoft.com). * The implementation was written so as to conform with Netscapes SSL. * * This library is free for commercial and non-commercial use as long as * the following conditions are aheared to. The following conditions * apply to all code found in this distribution, be it the RC4, RSA, * lhash, DES, etc., code; not just the SSL code. The SSL documentation * included with this distribution is covered by the same copyright terms * except that the holder is Tim Hudson (tjh@cryptsoft.com). * * Copyright remains Eric Young's, and as such any Copyright notices in * the code are not to be removed. * If this package is used in a product, Eric Young should be given attribution * as the author of the parts of the library used. * This can be in the form of a textual message at program startup or * in documentation (online or textual) provided with the package. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * 1. Redistributions of source code must retain the copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in the * documentation and/or other materials provided with the distribution. * 3. All advertising materials mentioning features or use of this software * must display the following acknowledgement: * "This product includes cryptographic software written by * Eric Young (eay@cryptsoft.com)" * The word 'cryptographic' can be left out if the rouines from the library * being used are not cryptographic related :-). * 4. If you include any Windows specific code (or a derivative thereof) from * the apps directory (application code) you must include an acknowledgement: * "This product includes software written by Tim Hudson (tjh@cryptsoft.com)" * * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * * The licence and distribution terms for any publically available version or * derivative of this code cannot be changed. i.e. this code cannot simply be * copied and put under another distribution licence * [including the GNU Public Licence.] */#include <errno.h>#include <time.h>#include <stdio.h>#include "cryptlib.h"#include "des_locl.h"#include <openssl/rand.h>/* * WARNINGS: * * - The data format used by DES_enc_write() and DES_enc_read() * has a cryptographic weakness: When asked to write more * than MAXWRITE bytes, DES_enc_write will split the data * into several chunks that are all encrypted * using the same IV. So don't use these functions unless you * are sure you know what you do (in which case you might * not want to use them anyway). * * - This code cannot handle non-blocking sockets. */int DES_enc_write(int fd, constvoid *_buf, int len,
DES_key_schedule *sched, DES_cblock *iv)
{
#ifdef _LIBCexternunsignedlong time();
externint write();
#endifconstunsignedchar *buf=_buf;
long rnum;
int i,j,k,outnum;
staticunsignedchar *outbuf=NULL;
unsignedchar shortbuf[8];
unsignedchar *p;
constunsignedchar *cp;
staticint start=1;
if (outbuf == NULL)
{
outbuf=OPENSSL_malloc(BSIZE+HDRSIZE);
if (outbuf == NULL) return(-1);
}
/* If we are sending less than 8 bytes, the same char will look * the same if we don't pad it out with random bytes */if (start)
{
start=0;
}
/* lets recurse if we want to send the data in small chunks */if (len > MAXWRITE)
{
j=0;
for (i=0; i<len; i+=k)
{
k=DES_enc_write(fd,&(buf[i]),
((len-i) > MAXWRITE)?MAXWRITE:(len-i),sched,iv);
if (k < 0)
return(k);
else
j+=k;
}
return(j);
}
/* write length first */
p=outbuf;
l2n(len,p);
/* pad short strings */if (len < 8)
{
cp=shortbuf;
memcpy(shortbuf,buf,len);
RAND_pseudo_bytes(shortbuf+len, 8-len);
rnum=8;
}
else
{
cp=buf;
rnum=((len+7)/8*8); /* round up to nearest eight */
}
if (DES_rw_mode & DES_PCBC_MODE)
DES_pcbc_encrypt(cp,&(outbuf[HDRSIZE]),(len<8)?8:len,sched,iv,
DES_ENCRYPT);
else
DES_cbc_encrypt(cp,&(outbuf[HDRSIZE]),(len<8)?8:len,sched,iv,
DES_ENCRYPT);
/* output */
outnum=rnum+HDRSIZE;
for (j=0; j<outnum; j+=i)
{
/* eay 26/08/92 I was not doing writing from where we * got up to. */
i=write(fd,(void *)&(outbuf[j]),outnum-j);
if (i == -1)
{
#ifdef EINTRif (errno == EINTR)
i=0;
else#endif/* This is really a bad error - very bad * It will stuff-up both ends. */return(-1);
}
}
return(len);
}